1. Field of the Invention
The present invention relates to a testing technique using a biomolecule, in particular a testing technique on a gene sequence such as a DNA sequencing analysis and a genetic diagnosis, and a testing technique on decomposition of a substrate by using an immobilized protein (enzyme), and a method for producing a substrate for making an analysis device used in the analysis of those as mentioned above.
2. Description of the Related Art
An analysis of a DNA sequence of genes including a human genome analysis has been rapidly progressing in recent years, and based on those information, it is advancing to a research on a gene function, a diagnosis on a disease caused by a gene, and so on. Furthermore, as a technique to perform analysis of these genes and research on a gene function in a large scale and in a short time, a number of researches on so-called a DNA chip and a DNA microarray are being made.
A DNA microarray is to detect a DNA strand having its complementary sequence in a sample by immobilizing a DNA with a specific sequence in a very narrow space. As a method for DNA immobilization, a stamping method using a pin, a bubble jet method (registered trade mark), and a method using a photolithography technique are known.
A substrate used for immobilizing these biomolecules is generally formed by introducing an amino group on its surface by applying mainly polylysine and an aminosilane on the substrate because a nucleic acid, an amino acid, and a protein may be immobilized on a substrate having an amino group.
However, in the method to apply polylysine and an aminosilane on a substrate as mentioned above, controls of a film thickness of polylysine and the aminosilane, and of a density and an orientation of the amino group are difficult, so that, in immobilization of a biomolecule, there are problems of causing a variation among substrates and a variation in amount of the immobilized biomolecule among immobilization spots. Depending on a processing method, these films may be delaminated in a certain case. These variations eventually lead to a fluctuation in detection results, which is a big problem in determining whether detected or not detected.
Accordingly, in order to improve a detection sensitivity of biomolecules such as a nucleic acid, an amino acid, and a protein, and also to establish a detection method of them, a method for producing a substrate for making a microarray having orientated amino groups toward an outmost surface in a controllable way to give uniform immobilization of a biomolecule on the entire surface without variation among substrates and variation in an immobilized amount among immobilization spots has been desired.